-pyrazolo(3,2-c)-s-triazole silver halide emulsions containing sensitizing dyes derived from a 1h

ABSTRACT

DYES DERIVED FROM 1H-PYRAZOLO(3,2-C)-S-TRIAZOLES ARE ADVANTAGEOUSLY USED IN PHOTOGRAPHIC SILVER HALIDE ELEMENTS AS SPECTRAL SENSITIZING DYES FOR THE SILVER HALIDE OR AS LIGHT-ABSORBING DYES FOR FILTER LAYERS.

United States Patent @lfice 3,758,309 Patented Sept. 11, 1973 3,758,309SILVER HALIDE EMULSIONS CONTAINING SENSITIZING DYES DERIVED FROM AIH-PYRAZOLO[3,2-c]-s-TRIAZOLE Joseph Bailey, Bushey Heath, and Edward B.Knott, Harrow, Middlesex, England, and Peter A. Marr, Rochester, N.Y.,assignors to Eastman Kodak Company, Rochester, N.Y.

N Drawing. Continuation-impart of abandoned application Ser. No.778,333, Nov. 12, 1968. This application Jan. 15, 1971, Ser. No. 106,893

Claims priority, application G/r igt Britain, Jan. 15, 1970,

S Int. Cl. G03c 1/18 U.S. Cl. 96-136 16 Claims ABSTRACT OF THEDISCLOSURE Dyes derived from lH-pyrazolo[3,2-c1-s-triazoles areadvantageously used in photographic silver halide elements as spectralsensitizing dyes for the silver halide or as light-absorbing dyes forfilter layers.

This application is a continuation-in-part of US. Ser. No. 778,333 filedon Nov. 12, 1968, now abandoned, and relates to photography, includingcolor photography, light-sensitive photographic emulsions containing adye derived from a 1H-p'yrazolo[3,2-c]-s-triazole and lightsensitiveelements in which at least one layer contains a dye derived from a1H-pyrazolo[3,2-c]-s-triazole.

It is known that certain methine dyes, including certain cyanine dyesand certain merocyanine dyes are useful in photographic elements assilver halide sensitizers and/or as light-filtering dyes. Dyes thatspectrally sensitize silver halide emulsions are particularly valuablefor use in color photography to differently sensitize the emulsionlayers so they will record light from the desired parts of the visiblespectrum. Color photographic elements usually comprise a support coatedwith an emulsion sensitive to light from the red region of the spectrum,an emulsion sensitive to light from the green region of the spectrum andan emulsion that is sensitive to light from the blue region of thespectrum. The layers may be arranged in various orders, however, oneconventional arrangement is to have the red-sensitive layer coated onthe support with the green-sensitive layer coated next, and thebluesensitive layer outermost, usually with a bleachable bluelight-absorbing filter layer coated between the greenand blue-sensitivelayers. [In addition to the bleachable blue light-absorbing filterlayer, other light-absorbing layers are used, either over, between orunder one or more of the light-sensitive layers.

Dyes must have not only the desired sensitizing characteristics and/orlight-absorbing characteristics but be readily soluble preferably inaqueous media for ease in sensitizing a photographic emulsion and alsofor ease in removal from the emulsion layers during photographicprocessing so that a minimum of stain is produced in the resultingphotograph. There is a continuing search for new dyes to fill the needsfor sensitizing and light-absorbing dyes for photography.

It is therefore an object of our invention to provide a novel class ofdyes derived from a 1H-pyrazolo[3,2-c]- s-triazoles of the indicatedtype that are valuable for use in photography as sensitizing dyes and/or light-filtering dyes.

Another object of our invention is to provide a novel hydrophiliccolloid silver halide emulsion containing one of our methine dyes.

Another object of our invention is to provide a novel photographicelement comprising a supoprt, at least one silver halide emulsion layerand at least one layer containing a methine dye derived from a1H-pyrazolo[3,2-c]- s-triazole.

Still other objects will be apparent from a consideration of thefollowing specification and claims.

These and still other objects are accomplished according to ourinvention by the preparation and use of our novel dyes derived from a1'H-pyrazolo[3,2-c]-s-triazole. Our dyes have two nuclei, at least oneof them being a 1H-p'yrazolo[3,2-c]-s-triazole nucleus attached at thecarbon atom in the 7 position of this nucleus through a double bond orby a methine linkage to a second nucleus to complete the dye, such as, asecond lH-pyrazolo- [3,2-c]-s-triazole nucleus, a heterocyclic basicnucleus having from 5 to 6 atoms in the heterocyclic ring in whichnitrogen, oxygen, sulfur and selenium are the heteroatoms with at leastone of the heteroatoms being nitrogen, including any of the Well-knownheterocyclic nuclei found in cyanine dyes or an acidic heterocyclicketomethylene nucleus having from 5 to 6 atoms in the heterocyclic ringwith heteroatoms such as nitrogen, oxygen, sulfur and selenium,including any of the well-known acidic heterocyclic ketomethylene nucleifound in meroicyanine dyes.

In one embodiment of our invention, our methine dyes have two1H-pyrazolo[3,2-c]-s-triazole nuclei connected to each other through thecarbon atom in the 7 position of the nuclei by a conjugated methinelinkage having an odd number of from 1 to 5 (i.e., l, 3 or 5) carbonatoms' in the linkage.

In another embodiment of our invention, our dyes have alH-pyrazolo[3,2-c]-s-triazole nucleus attached at the carbon atom in the7 position of this nucleus through a double bond or a methine linkage toa car-bon atom in a second nucleus that is a heterocyclic basic nucleushaving from 5 to 6 atoms in the heterocyclic ring such as are found incyanine dyes.

In another embodiment of our invention, our dyes Have al-H-pyrazolo[3,2-c]-s-triazole nucleus attached at the carbon atom inthe 7 position of this nucleus by a conjugated methine linkage having anodd number of from 1 to 5 (La, 1, 3, or 5) carbon atoms in the linkage,to a carbon atom in a second nucleus that is an acidic heterocyclicketomethylene nucleus having from 5 to 6 atoms in the heterocyclic ring,including any of the acidic heterocyclic ketomethylene nuclei found inmerocyanine dyes.

The dyes of our invention are derived from a 1H-pyrazolo[3,2-c]-s-triazole advantageously represented by the formulas:

wherein R, R R and R each represent the same or a different group, suchas, a hydrogen, an alkyl group that is straight chain or branched chain,preferably having from 1 to 22 carbon atoms and unsubstituted orsubstituted, such as, methyl, ethyl, n-propyl, isopropyl, sec. butyl,t-butyl, t-amyl, hexyl, 2-chlorobutyl, 2-hydroxyethyl, Z-phenylethyl,2-(2,4,6-trichlorophenyl)ethyl, etc.; an aryl group that isunsubstituted or substituted, in which the aryl group is a naphthylgroup, e.g., a-naphthyl, fi-naphthyl, 2-chloro-y-naphthyl,2-methoxynaphthyl, etc., a phenyl group (eg, 4-methylphen'yl,2,4,6-trichlorophenyl, 3,5 dibromophenyl, 2-, 3-,4-trifiuoromethylphenyl, etc., a heterocyclic group having from 5 to 6atoms in the ring, e.g., a pyridyl group, a thienyl group, a quinolylgroup, and furyl group etc.; amino; substituted amino, e.g.,methylamino, diethylamino, n-docosylamino, phenylamino, tolylamino,4-(3-sulfobenzamido)anilino, 4-cyanophenylamino,Z-tri-fluoromethylphenylamino, benzothia-zoloamino, etc.; acylamidoradicals, e.g., ethylcarbonarnido, butylcarbonamido, phenylethylcarbonamdo, phenylcarbonamido, 2,4,6 trichlorophenylcarbonamido, 4methylphenylcarbonamido, 2 ethoxyphenylcarbonamido, 2 [(2,4di-tert-amylphenoxy) acetam1do1benzamido, 'yor p-naphthylcarbonamido,etc.; hydroxy; an alkoxy group, e.g., methoxy, ethoxy, n-butoxy;n-hexoxy, etc.; carboxy; an esterified carboxy radlcal, such as, a

(Ha) (11b) RXNH R wherein R, R R and 'R3 are as defined previously,while Q and Q represent the atoms necessary to complete the chromophoricsystem. Q, for example, represents a group, etc., and Q, for example,represents a group, etc., wherein -L represents a methine group (e.g.,CD= where D represents hydrogen, a lower alkyl group, such as, methyl,ethyl, butyl, etc., and an aryl group such as phenyl, tolyl, naphthyl,etc.) such that not more than one L group contains a D group other thanhydrogen; n represents an integer of from to 2; R and R are as describedpreviously; Z represents the atoms necessary to complete a heterocyclicbasic nucleus having from to 6 atoms in the heterocyclic ring such asthose conventionally employed in cyanine dyes, especially including2-pyrrole, 3-pyrrole, 2-indole, 3-indole, 1-1Ild0llzine, 3-indolizine,etc.; Z represents the atoms necessary to complete an acidicheterocyclic ketomethyl ene nucleus having from 5 to 6 atoms in theheterocychc ring conventionally employed in merocyanine dyes, such as, ahydantoin nucleus (e.g., hydantoin, 3-alkyl (e.g., ethyl, propyl, etc.)hydantoin, 3-phenyl, or 3-a-naphthy1 hydantoin, 1,3-dialkyl (e.g.,1,3-diethyl, etc.) hydantorn, l-alkyl-3-aryl (e.g., 1-methyl-3-phenyl,1-n1ethyl-3-naphthyl, etc.) hydantoin, 1,3-diphenyl hydantorn, etc., athrohydantoin nucleus (e.g., 2-thiohydantoin, 3-methyl-2-th1ohydantoin,1,3-diethyl 2 thiohydantoin, 1,3- d1pheny1-2- thiohydantoin,1-ethy1-3-phenyl-2-thiohydantom, etc.), a rhodanine nucleus (e.g.,rhodanine, 3-ethy1rhodamne, 3-pheny1rhodanine, 3-m-naphthylrhodanine,3-(1-benzothiazy1)rhodanine, etc.), a barbituric acid nucleus (e.g.,barbituric acid, l-ethyl barbituric acid, 1,3-diethyl barbituric acid, ea thiobarbituric acid nucleus (cg.

2-thiobarbituric acid, 1-propyl-2-thiobarbituric acid,l-phenyl-Z-thiobarbituric acid, 1,3-diethyl-2-thiobarbitunc acid, etc.),a 2-thiazolin-4-one nucleus (e.g., Z-thiazolin- 4-one,3-methyl-2-thiazolin-4-0ne, etc.), a 2-thio-2,4- oxazolinedione nucleus(e.g., 2-thio-2,4-oxazolinedione, 3-ethyl-2-thio-2,4-oxazolidinedione,etc.), an imidazolone nucleus (e.g., 2-imidazolin-4-one, etc.), a2-pyrazolin-5- one nucleus (e.g., 2-pyrazolin-5-one,l-phenyl-Z-pyrazolin- 5-0ne, 3-anilino-2-pyrazolin-5-one, etc.), anindandione nucleus (e.g., indandione, etc.), etc.; Z represents thenonmetallic atoms required to complete a 5 to 6 membered heterocycliobasic nucleus of the type found in cyanine dyes, such as, a thiazolenucleus (e.g., thiazole, 4-methyl thiazole, 4-phenylthiazole,S-methylthiazole, S-phenylthiazole, 4,5-dimethylthiazole,4,5-diphenylthiazole, 4-(2-thienyl) thiazole, etc.), a benzothiazolenucleus (e.g., benzothiazole, 4-chlorobenzothiazole,S-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole,4-methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole,5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole,S-phenylbenzothiazole, 4-methoxybenzothiazole, S-methoxybenzothiazole,6-methoxybenzothiazole, S-iodobenzothiazole, 6-iodobenzothiazole,4-ethoxybenzothiazole, S-ethoxybenzothiazole, tetrahydrobenzothiazole,5,6 dimethoxybenzothiazole, 5,6 dioxymethylenebenzothiazole, 5-hydroxybenzothiazole, -hydroxybenzothiazole, etc.), a naphthothiazolenucleus (e.g., u naphthothiazole, )8 naphthothiazole, 5 methoxy anaphthothiazole, 5-ethoxy-a-naphthothiazole,8-methoxy,6-naphthothiazole, 7-methoxy-a-naphthothiazole, etc.), athionaphtheno-7',6',4,5-thiazole nucleus (e.g., 4-methoxythianaphtheno7,6,4,5-thiazole, etc.), an oxazole nucleus (e.g., 4-methyloxazole,S-Inethyloxazole, 4-phenyloxazo1e, 4,5-diphenyloxazole, 4-ethy1-oxazole, 4,5-dimethyloxazole, S-phenyloxazole, etc.), a benzoxazolenucleus (e.g., benzoxazole, S-chlorobenzoxazole, 5 methyl benzoxazole, 5phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole,4,6-dimethylbenzoxazole, 5 -methoxybenzoxazole, 5 -ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole, S-hydroxybenzoxazole,6-hydroxybenzoxazole, etc.), a naphthoxazole nucleus (e.g.,a-naphthoxazole, ,B-naphthoxazole, etc.), a selenazole nucleus (e.g.,4-methylselenazole, 4-phenylselenazole, etc.), a benzoselenazole nucleus(e.g., benzoselenazole, S-chlorobenzoselenazole, 5methoxybenzoselenazole, 5 hydroxybenzoselenazole,tetrahydrobenzoselenazole, etc.), a naphthoselenazole nucleus (e.g.,a-naphthoselenazole, B-naphthoselenazole, etc.), a thiazoline nucleus(e.g., thiazoline, 4-methylthiazoline, etc.), a 2-pyridine nucleus(e.g., 2-pyridine, 5-methyl-2-pyridine, etc.), a 4-pyridine nucleus(e.g., 4-pyridine, 3-methyl-4-pyridine, etc.), a 2-quinoline nucleus(e.g., 2-quinoline, 3-methyl-2-quinoline, 5-ethyl-2- quinoline,6-chloro-2-quinol1'ne, 8-chloro-2-quinoline, 6-methoxy-2-quinoline,8-ethoxy-2-quinoline, 8-hydroxy- 2-quinoline, etc.), a 4-quinolinenucleus (e.g., 4-quinoline, 6-methoxy-4-quinoline, 7-methyl-4-quinoline,8-chloro-4-quinoline, etc.), a l-isoquinoline nucleus (e.g.,l-isoquinoline, 3,4-dihydro-l-isoquinoline, etc.), a 3-isoquinolinenucleus (e.g., 3-isoquinoline, etc.), a 3,3-dialkylindolenine nucleus(e.g., 3,3-dimethy1indolenine, 3,3,5- trimethylindolenine,3,3,7-trimethylindolenine, etc.), an imidazole nucleus (e.g., imidazole,l-alkylimidazole, 1-alkyl-4-phenylimidazole,1-alkyl-4,S-dimethylimidazole, etc.), a benzimidazole nucleus (e.g.,benzimidazole, l-alkylbenzimidazole, l aryl-S,6-dichlorobenzimidazole,etc.), a naphthimidazole nucleus (e.g., l-alkyl-a-naphthimidazole,l-aryl-fl-naphthin'lidazole, l-alkyl-S-methoxy- 3-naphthimidazole,etc.), etc.; R represents an alkyl group (e.g., methyl, ethyl,sulfoethyl, carboxyethyl, propyl, butyl, etc.) and a phenyl group (e.g.,phenyl, tolyl, etc.); X represents an acid anion (e.g., Cl, (Br, 1",H804", 021158047, p-CH C H CO CLOI, 1803 SCN-, etc.) and m is 1 or 2.

Our dyes are still further represented by the dyes of Formulas III, IV,VI and VIII which are described herein below.

Dyes of Formula III:

wherein R, R L, Z R and X are as defined previously, are advantageouslyprepared by reaction of a compound of Formula Ia with a compound of theFormula V:

wherein L, n, Z and R are as defined in the presence of an acid HX.These dyes are advantageously used as filter dyes which are bleachablein photographic developer solutions.

Dyes of the Formula VI.

R NH t.

wherein R, R L, n and Z are as defined previously, are advantageouslyprepared by reaction of a compound of Formula I with a compound havingthe Formula VII:

r- W Y1OH=(LL=),1CG=O wherein Y is alkoxy or acetanilido. Dyes ofFormula VI are advantageously used to spectrally sensitize photographicsilver halide emulsions.

Dyes of the Formula VIII:

wherein R, R L, n, R 'and Z are as defined previously,

are advantageously prepared by reaction of a compound of Formula Ia witha compound of the Formula IX:

wherein Y; is iodine, ethylthio, or an acetanilido radical. Dyes ofFormula VIII are advantageously used as spectral sensitizers for silverhalide emulsions.

The compounds of Formulas I and la are advantageously prepared byheating the appropriate 7-alkoxycarbonyl-lH-pyrazolo[3,2-c]-s-triazole(substituted or not on the carbon atoms in the 3 and 6 positions on thering) in sulfuric acid to remove the 7-alkoxycarbonyl group byhydrolysis. The 7-alkoxycarbonyl-lH-pyrazolo [3,2-c]-s-triazoles areadvantageously prepared by adding a solution of bromine in glacialacetic acid to a mixture of benzaldehyde4-ethoxycarbonyl-3-methylpyrazol-S-yl hydrazone [II. Beyer et al., Ber.89, 2552 (1956)] or by acylation of the appropriate4-ethoxycarbonylpyrazol-S- yl hydrazine with the appropriate acidchloride or acid anhydride while heating, after which the acylatedcompound is heated under reflux with a dry inert solvent, such as,benzene, toluene, etc., and phosphorous oxychloride to cause ringclosure and formation of the desired 7-alkoxycarbonyl lI-Ipyrazolo[3,2-c]-s-triazole. Compounds of Formulas I and Ia in which R isa substituted amino group are advantageously prepared by heating theappropriate 4-ethoxycarbonyl pyrazol-S-yl hydrazine with the appropriateisocyanate of the Formula RNCO in an inert solvent, isolating theproduct then ring closing with phosphorous oxychloride, and subsequentlyhydrolyzing the 4-ethoxycarbonyl group from the compound. Compounds ofFormulas I and Ia, where R is an alkylthio radical, and R is a branchedalkyl or aryl, may also be conveniently obtained by reacting anisothiocarbohydrazide hydrohalide exemplified by compounds of theformula such as prepared with the corresponding thiocarbohydrazide andalkyl halide; with a keto ester of the formula R COCH COOR at atemperature of about 75 l30 C. to directly obtain the bi-cyclicintermediate as follows:

RJI i EXAMPLE 1 7-(6-methyl-3-phenyl 1H pyrazolo[3,2-c]-s-triazol-7-ylidene)methylene =6 methyl-3-phenyl-lI-I-pyrazolo [3,2-c]-s-triazole6-methyl-3-phenyl-1H-pyrazolo[3,2 c]-s-triazole (50 mg.) in acetic acid(2 cc.) is treated with ethyl orthoformate (0.5 cc.). Yellow dyeimmediately forms and on stirring the product, crystallizes. It iscollected by filtration and washed with acetic acid. The dye issuspended in boiling ethanol and after cooling is collected byfiltration and 'washed with ethanol. The yield of dye is almosttheoretical. The dye is soluble in a mixture of ethanol and aqueouscaustic soda. It has an absorption maximum in pyridine at 483 mg. Thedye sensitizes a silver chlorobromide emulsion out to 565 nm. with apeak at 450 run. when utilized at a concentration of 200 mg./mole ofsilver.

The following dyes are prepared using procedures similar to thatdescribed in Example 1 with the appropriate intermediates:

7- 6-methyl-3-p-tolyllH-pyrazolo 3,2-c] -s-triazol-6- ylidenemethylene-6-methyl-3 -p-tolyllH-pyrazolo [3,2-c] -s-triazole,

7- (6-methyl-3-n-propyl-1H-pyrazolo[3,2-c] -s-triazol-7- ylidene)methylene-6-methyl-3-n-propyllH-pyrazolo [3,2-c] -s-triazole,

7-(6-methyl-3-p-meth0xyphenyl-1Hpyrazolo[3 ,Z-c] -striazol-7-ylidenemethylene-6-methyl-3 -p-methoxyphenyl-1H-pyrazolo[3 ,2-c] -s-triazoleand 7-(6-methyl-3-(2,6-dichlorophenyl)-1H-pyrazolo [3,2-c]

s-triazol-7-ylidene methylene-6-methyl-3- 2,6-dichlorophenyl)-1H-pyrazolo [3,2-c] -s-triazole.

EXAMPLE 2 7-(3,6 dimethyl 1Hpyrazolo[3,2-c]-s-triazol-7-ylidene)-3-allylidene 3,6dimethyl-1H-pyrazolo[3,2- c] -s-triazole3,6-dimethyl-lH-pyrazolo[3(2-c]-s-triazole (50 mg.) in

acetic acid (2 cc.) is treated with B-ethoxyacrolein acetal (0.5 cc.). Amagenta dye is formed immediately and the mixture is warmed on the steambath for two minutes and after cooling the dye precipitates by additionof ether.

The product is collected by filtration and Washed with ether. The yieldis almost theoretical. The dye has an absorption maximum in methanol at542 m and is bleached by a developer, such as, Kodak (a registeredtrademark) D19 developer.

The following dyes are prepared using procedures similar to thatdescribed in Example 2 with the appropriate intermediates:

7- (6-methyl-3-phenyllH-pyrazolo [3 ,2-c] -s-triazol-7- ylidene) -3-allylidene-6-methyl-3 phenyllH-pyrazolo [3 ,2-c] -s-triazole,

7- (6-methyl-3-p-tolyl-1 H-pyrazolo[ 3 ,2-c] -s-triazol-7- ylidene) -3'-ally1idene-6-methyl-3-p-tolyllH-pyrazolo [3,2-c] -s-tri'azole,

7 (6-methyl-3 -n-propyl-1H-pyrazolo [3 ,2-c] -s-triazol-7- ylidene) -3-allylidene-6-methyl-3-n-propyl-lH-pyrazolo [3,2-c] -s-triazole and 7-6-methyl-3 -p-methoxyphenyllH-pyrazolo [3 ,2-c]

s-triazol-7-ylidene) -3'-allylidene-6-methy13-p-methoxyphenyllH-pyrazolo [3 ,2-c] -s-tri azole.

EXAMPLE 3 7 (1,3 diethyl4,6-dioxo-hexahydro-2-thio-5-pyrimidylidene)-3-allylidene-3,6-dimethy1-1Hpyrazolo[3,2-c]- s-triazole 3,6-dimethy1-1H-pyrazolo [3,2-c]-s-triazole(0.14 gram) and 1,3-diethyl-4,6-dioxo-5-(3ethoxyallylidene)hexahydro-Z-thiopyrimidine (0.28 gram) are warmed inethanol (5 ml.) on a steam bath for -5 minutes and the magenta dye isprecipitated by pouring into water (25 -ml.). The product which isobtained in almost theoretical amount is collected and dried. It has anabsorption maximum in methanol at 539 m The following dyes are preparedusing procedures similar to that described in Example 3 with theappropriate intermediates.

7 1,3-diethyl-4,6-dioxo-hexahydro-2-thioS-pyrimidylidene3'-allylidene-6-methyl-3 -phenyl-1H-pyrazolo [3,2-c] -s-triazole,

7 1,3-diethyl-4,6-dioxo-hexahydro-2-thio-5-pyrimidylidene) 3'-allylidene-6-methyl-3 -p-toly1- lH-pyrazolo [3 ,2-c] -s-triazole,

7 3-phenyl-2-thio-4-oxo-5-thiazolidylidene -3 '-allylidene-6-methyl-3-p-methoxyphenyl-lH-pyrazolo [3,2-c] s-triazole and 73-phenyl-2-thio-4-oxo-5-thiazolidylidene) -3 '-allylidene- 6-m'ethyl-3-(2,6-dichlorophenyl) -1Hpyra golo[3,2-c] s-triazole.

EXAMPLE 4 3 -eth yl-2- (3 6-dimethyllH-pyrazolo [3 ,2-c] -s-triazol-7-ylidene -2'-ethylidenebenzthiazoline3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazole (0.14 gram) 2-2-acetanilidovinylbenzthiazole ethiodide (0.45 gram), triethylarnine (0.5 ml.) andethanol (25 ml.) are heated together on a steam bath for 10 minutes.After cooling, ether ml.) is added and the product separates. The yieldof dye is 0.1 gram. It has an absorption maximum in methanol at 494 mg.

The following dyes are prepared using procedures similar to thatdescribed in Example 4 with the appropriate intermediates.

3-ethy1-2- 3 ,6-dimethyllH-pyrazolo 3,2-c] -s-triazo1- 7-ylidene-2-ethylidene-benzo selenazoline, 3 -ethyl-2- 6-methyl-3-p-methoxyphenyllH-pyrazolo [3 2-c] -s-triazol-7-ylidene(-2-ethylidene-b enzothiazoline, 3 -ethyl-2-(6-methyl-3-pmethoxyphenyllH-pyrazolo [3 ,2-c] -s-trazol-7-ylidene-2'-ethylidene-benzoxazoline, 1,3-diethyl-2- 3,6-dimethyllH-pyrazolo3,2-c] -s-triazol- 7-ylidene) -2'-ethylidene-benzimidazoline and1-ethyl-2- (3 ,G-dimethyl-lH-pyrazolo [3,2-c] -s-triazol- 7-ylidene)-2'-ethylidene-1,2-dihydroquinoline.

EXAMPLE 5 l-ethyl-2,5-dimethyl-3- 3,6-dimethyl-1H-pyrazolo[3,2-c]s-triazol-7-ylidene)methylenepyrrole3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazole (0.14 gram)1-ethyl-2,5-dimethyl-3-pyrrole aldehyde (0.12 gram) and acetic acid (1ml.) are warmed together on a steam bath for 5 minutes to given a yellowdye which is isolated by removing the acetic acid in vacuo. The dye hasan absorption maximum in methanol at 436 my and is bleached by adeveloper, such as, Kodak D19 developer.

The following dyes are prepared using procedures similar to that used inExample 5 with the appropriate intermediates.

EXAMPLE 6 7 (1,3 diethyl-4,6-dioxo-hexahydro-2-thio-S-pyrimidylldene) -3'-allylidene-3 -p-dimethylaminophenyl-6-methyllH-pyrazolo[3,2-c]-s-triazole The dye is prepared by the method ofExample 3 using 3 (p dimethylaminophenyl) 6 -methy1-1H-pyrazolo[3,2-c]-s-triazole instead of 3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazole.

EXAMPLE 7 7 (1,3 diethyl-4,6-dioxo-hexahydro-Z-thio-S-pyrimidylldene) 3'allylidene-3-(2,6-dichlorophenyl-6-methyllH-pyrazolo[3,2-c]-s-triazoleThe dye is prepared by the method of Example 3 using3-(2,6'-dichlorophenyl)-6-methyl 1H pyrazolo [3,2-c1-s-triazole insteadof 3,6-dimethyl-1H-pyrazo10 [3,2-c]-s-triazole.

EXAMPLE 8 3-ethyl-2-(6-methyl-3-phenyl-1H-pyrazolo[3,2-c]-s-triazole-7-ylidene)-2'-ethylidenebenzoxazoline 6methyl-S-phenyl-1H-pyrazolo[3,2-c]-s-triazole (0.2 gram),2-2'-acetanilidovinylbenzoxazole ethiodide (0.45 gram) and triethylamine(0.42 ml.) in ethanol (20 ml.) are heated together on a steam bath for10 minutes. The mixture is cooled and diluted with water (10 ml.) toprecipitate the product which is recrystallized from aqueous ethanol asorange crystals.

EXAMPLE 9 3-ethyl-2-(6-methyl-3-phenyl-lH-pyrazolo[3,2-c]-s-triazole-7-ylidene)-2'-ethylidenebenzothiazoline This compound isprepared from 6-methyl-3-phenyllH-pyrazolo[3,2-c1-s-triazole and2-2'-acetanilidovinylbenzthiazole ethiodide in ethanol in the presenceof triethylamine by the method of Example 4.

The product, which is isolated in the form of red platelets, sensitizesa silver chlorobromide emulsion out to 600 nm. with peaks at 510 and 560nm.

EXAMPLE l -(6-methyl-3-phenyl-lH-pyrazolo[3,2-c]-s-triazol-7-yl)methylene-3-phenyl-2-thiothiazolid-4-one 6 methyl 3 phenyl 1Hpyrazolo[3,2-c]-s-triazole (0.2 gram),5-eth0xymethylene-3-phenylrhodanine and triethylamine (0.42 ml.) inethanol (20 ml.) are heated on a steam bath for 10 minutes and aftercooling, the reaction mixture is acidified with dilute hydrochloricacid. The separated product is collected by filtration andrecrystallized from benzene as yellow-orange needles.

The product sensitizes a silver chlorobromide emulsion out to 610 nm.with a peak at 570 nm.

The following dyes are prepared using procedures similar to thatdescribed in Example 10 with the appropriate intermediates.

5-(6-methyl-3-phenyl-1H-pyrazolo[3,2-c]-s-triazol-7-yl)methylene-1,3-diethyl-2-thiobarbituric acid,

5-(3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazol-7-yl)methylene-1,3-diethyl-2-thiobarbituricacid and 5-(3,6-dimethyl-1H-pyrazolo[3,2-c]-s-triazol-7-yl)methylene-3-phenyl-2-thiothiazolid-4-one.

The following Examples 11 through 14 illustrate the reactions used tosynthesize compounds of Formulas I and Ia used in Examples 1 through 10above.

EXAMPLE 1 1 6-methyl-3-phenyl- IH-pyrazolo [3,2-c] -s-triazole 7ethoxycarbonyl-6-methyl-3-phenyl 1H pyrazolo- [3,2-c]-s-triazole (1gram) and sulfuric acid (sp. gr. 1.84; 8 ml.) are warmed on steam bathat 60-70 C. for 45 minutes. The clear reaction solution is cooled andpoured into water (200 ml). The thick colorless precipitate is collectedby filtration, washed with sulfuric acid (3 N, 25 ml.) and then withwater (50 ml.). The product is recrystallized from aqueous ethanol andobtained as bulf needles. The yield is 0.4 gram (55%). C H N requires66.7% C; 5.1% H; 28.3% N; sample on analysis gives 66.8% C; 5.3% H;27.85% N.

EXAMPLE l2 3-p-dimethylaminophenyl-G-methyl-lH-pyrazolo-[3,2-c]-s-triazole The method of preparation is similar to Example 11using the appropriate intermediate. The intermediate used is prepared byreaction of p-dimethylaminobenzaldehyde with 4 ethoxycarbonyl 3 methylpyrazol 5 yl hydrazine and ring closure of the resulting hydrazone by 10mixing it with sodium acetate in acetic acid and adding to the mixture asolution of bromine in glacial acetc acid.

EXAMPLE 13 3,6-dimethyllH-pyrazolo [3 ,2-c] -s-triazole 4 ethoxycarbonyl3 methylpyrazolo 5 yl hydrazine [H. Beyer et al. Ber. 89, 2552 (1956)](3.09 grams) is mixed with acetic acid (10 ml.) and acetic anhydride(1.5 ml.) and heated on steam bath for 1 hour. The solution is cooled,poured into water (50 ml.) and the crystalline acethydrazide iscollected, after chilling overnight, washed with ice cold water anddried. The product which weighs 3.14 grams (98%); MP. C. is heated underreflux with dry benzene (125 ml.) and phosphorus oxychloride (2.7 ml.)for 4 hours and then stood overnight at room temperature. The benzene isremoved by distillation and the residual oil is stirred with water (100ml.). The mixture is extracted with ethyl acetate (3X ml.). The ethylacetate solution is dried over calcium sulfate and then concentrated todryness yielding a pale yellow solid which is recrystallized fromethanol. The product which weighs 2.05 grams and melts at 172- 3 C. istreated with concentrated sulfuric acid (16 ml.) and heated on a steambath for 75 minutes. The solution is then cooled and poured into water(100 ml.) and, after chilling, is basified to pH 10 with 40% sodiumhydroxide solution. The solution is extracted with ethyl acetate (3X 150ml.) and the organic layer separates, is dried over calcium sulfate and,after removing the solevnt by distillation, a pale yellow solid isobtained. The product weighs 1.1 gram and melts at C.

EXAMPLE 14 3-(2,6-dichlorophenyl)-6-methyl-1H-pyrazolo[3,2-c]-s-triazole-7-carboxylic acid 3 methylthio 6 phenyllH-pyrazolo[3,2-c]-s-triazole (Compound 15) UTSCHS Ethyl benzoylacetate(9.6 grams) and S-methyl isothiocarbohydrazide hydriodide (12.4 grams)were heated to gether at l10-l15 C. for 25 minutes.. During the last 5minutes of the heating the volatile reactants were distilled olf invacuo. The reaction mixture was cooled and then heated with suflicientboiling 10% sodium carbonate solution (about 300 ml.) to effect solutionof most of the reaction mass. A small amount of oily residue remainedwhich was removed by filtration. On cooling the hot clear carbonatesolution the product crystallized and was collected by filtration. Itwas recrystallized from benzene as tiny buff-coloured needles. The yieldof product which melted at 179 C. was 5 grams. It coupled with oxidized2-amino-5-diethylaminotoluene developer to give a dye which had A ethylacetate at 565 nm. The S- methyl isothiocarbohydrazide hydriodide wasprepared by adding methyl iodide (18 grams) to a well stirred suspensionof thiocarbohydrazide (12 grams) in boiling ethanol (400 ml.) andheating under reflux for 2 hours.

Ethyl m-nitrobenzoyl acetate (2.4 grams) and S- methylisothiocarbohydrazide hydriodide (2.5 grams) were heated at 120 C. for15 minutes. The reaction mass was treated with carbonate solution asdescribed in the previous example. The dark yellow solid product, whichseparated was collected, melted at 2l4217 C. and coupled with oxidized2-amino-S-diethylaminotoluene developer to give a dye having x ethylacetate at 5 85 nm.

EXAMPLE 17 6-heptadecyl-3 -methylthio-1H-pyrazolo [3 ,2-c] -s-triazoleN--Nl[S 0 H A solution of ethyl stearoylacetate (2.1 grams) and S-methyl isothiocarbohydrazide hydriodide (1.6 grams) in n-amyl alcohol(25 ml.) Was heated under reflux for 2 hours. On cooling some solidmaterial separated and was collected by filtration. Ether was added tothe amyl alco hol solution to precipitate more solid material which wasalso filtered off. Neither solid coupled with oxidized developers. Thesolution was concentrated to leave an oil which was treated with benzene(100 ml.) and the solvent again removed. The residual gum (2 grams)coupled with oxidized Z-arnino-S-diethylamino toluene developer to givea dye having A ethyl acetate at 541 nm.

EXAMPLE 18 2-methylthio-6-p-nitrophenyl-1H-pyrazolo[3,2-c]- s-triazoleNNH-S CH3 H OgN EXAMPLE 193-methylthio-6-propyl-lH-pyrazolo[3,2-c]-s-triazole NN SCH I if Thiscompound was prepared similarly to Example 17 using a proportionateamount of ethyl butyrylacetate instead of ethyl stearoylacetate. Theproduct which was obtained as a gum coupled with oxidised2-amino-5-diethylaminotoluene developer to give a dye with k ethylacetate at 541 nm.

EXAMPLE 20 This compound was prepared as Example 17 usingethyl-2-furoylacetate instead of ethyl stearoylacetate. The productwhich was obtained as a gum coupled with oxidised2-amino-S-diethylaminotoluene developer to give a dye having a A ethylacetate at 567 nm.

NN SCH;

CH S N O-ethyl-S-methyl asymmetric diethiomalonate (1.78 grams) (Laakso,Suomen Kemistilehte, 1944, 17B, 1-6) and S-methyl isothiocarbohydrazide(2.36 grams) were heated in boiling amyl alcohol (25 ml.) for 30 minutesand worked up as in Example 3. The product which was obtained as a gumcoupled with oxidised 2-amino-5-diethylamino toluene developer to give adye having A ethyl acetate at 533 nm.

EMMPLE 22 7-bromo-3-methylthio-6-phenyl-lH-pyrazolo[3,2-c1- s-triazole HBr Compound -15 (1 gram), sodium acetate (0.2 gram) were dissolved inacetic acid (30 ml.) and the solution was treated with bromine (0.8gram) in acetic acid (4 ml.) portionwise. The mixture was allowed tostand at room temperature for 40 minutes and then heated on a steam bathfor '20 minutes, after which it was cooled back to room temperature andpoured into water ml.). The precipitated product was collected byfiltration, washed with water and dried. It weighed 1.1 grams, melted at152153 and coupled with oxidised Z-amino-S-diethylamino toluenedeveloper to give a magenta dye.

EXAMPLE 23 7-chloro-3-methylthio-6-phenyl-lH-pyrazolo [3,2-c1-s-triazole caHbi/LN Compound 15 (1 gram) was dissolved in acetic acid(15 ml.) and sulphuryl chloride (0.65 gram) were slowly added to thesolution, the mixture was heated on the steam bath for 5 minutes andallowed to stand at room temperature for 1 hour. The mixture was thenpoured into water (200 ml.) and the precipitated product was collectedby filtration and dried. It weighed 0.9 gram and melted at 150.

13 EXAMPLE 24 7 (3 methylthio 6 phenyl 7H pyrazolo[3,2 c]-striazol 7ylidene) methylene 3 methylthio-6- phenyl 1 H- pyrazolo[3,2 c] striazole SCHl Compound 15 (0.1 gram), ethylorthoformate (1 ml.) andacetic acid (4 ml.) were heated at boiling point for 5 minutes. Theproduct which crystallized from the hot reaction mixture was isolatedafter cooling by filtration. It was washed with ethanol, dried andobtained in almost theoretical amount. It has an absorption maximum inmethanol in the presence of triethylamine at 494 nm.

EXAMPLE 25 7,3'-(3 methylthio 6phenyl-7H-pyrazolo[3,2-c]-s-triazol-7-ylidene)allylidene 3methylthio-6-phenyl-1H- pyrazolo[3,2-c]-s-triazole (Compound 25) Asolution of Compound 15 (0.23 gram) and 1,1,3-trimethoxy-3-ethoxypropane(0.2 ml.) in acetic acid (5 ml.) was heated under reflux for 2 minutes.The solid dye product separated from solution and after cooling it wascollected and recrystallized in almost quantitative yield from methanol.The product was obtained as dark green metallic crystals A methanol at554 nm.

EXAMPLE 26 3-ethyl-2-(3-methylthio 6phenyl-7H-pyrazolo[3,2-c1-striazole-7-ylidene)benzthiazoline (Compound26) Compound 15 (0.23 gram), Z-ethylthiobenzthiazole ethiodide (0.34gram), triethylamine (0.5 ml.) and ethanol (5 ml.) were heated underreflux for 10 mins. After chilling the reaction mixture, the separateddye was collected and recrystallised from ethanol as pale yellowcrystals. It weighed 0.1 gram and had A methanol at 410 nm.

EXAMPLE 27 3-methylthio-7-p-nitrobenzylidene-6-phenyl-7H- pyrazolo [3,2-c] -s-triazole CgH Compound (0.23 gram), p-nitrobenzaldehyde andacetic acid (5 ml.) were heated under reflux for 10 mins. After coolingthe product was precipitated by dilution with water (25 ml.) andcollected by filtration. It was twice recrystallised from ethanol andobtained in as pale yellow crystals. It coupled with oxidized 2-amino-S-diethylamino toluene developer to give a dye A ethyl acetate at 565nm.

EXAMPLE 28 71-ethy1-2,5-dimethyl-3-pyrryl)methylene-3-methylthio-6-pheny1-7H-pyrazolo[3,2-c] -s-triazole N C J-CH,

N CHaS N Compound 15 (0.46 gram), 1-ethyl-2,5-dimethylpyrrol- 3-aldehyde(0.3 gram) were dissolved in boiling ethanol (10 ml.) and triethylamine(1 ml.) was added and the solution was refluxed for 10 minutes. Thesolution was concentrated to 5 ml. and well chilled when the dye product(0.25 gram) separated. It was twice recrystallised from methanol giving0.15 gram orange needles. The dye has A methanol at 447 nm.

EXAMPLE 29 5-(3-methylthio 6 phenyl-lH-pyrazolo[3,2-c1-s-triazol-7-yl)methylene 3 phenyl-2-thiothiazolid-4-one (Compound 29) EXAMPLE 303-ethyl-2,2'-(3 methylthio 6 phenyl-1H-pyrazolo[3,2- cJ-s-triazole7-ylidene)ethylidenebenzoxazoline (Compound 30) N err-on l N/ zHB on.

A mixture of Compound 15 (.23 gram) 2,2'-acetanilidovinylbenzoxazoleethiodide (0.45 gram), triethylamine (0.42 ml.) and ethanol (20 ml.) washeated under reflux for 10 minutes. Water (20 ml.) was added to thecooled reaction solution and the product which was obtained in almostquantitative yield was recrystallised from methanol as yellow crystalshaving A methanol at 480 nm.

1 5 EXAMPLE 31 3-ethyl-2,2'-(3 -methylthio 6 phenyl-7H-pyrazolo[3,2-c]-s-triazol 7-ylidene)ethylidenebenzthiazoline (Com- It ems Compound(0.46 gram) 2,2'-acetanilidovinylbenzthiazole ethiodide (0.9 gram),triethylamine (1 ml.) and 15 ethanol (30 ml.) were heated together on asteam bath for 10 minutes. The reaction mixture was cooled and theseparated product was collected by filtration. It was recrystallisedtwice from methanol. The purified product weighed 0.2 gram and has Amethanol at 521 nm.

EXAMPLE 32 7,3-(1,3-diethyl 4,6 dioxo-hexahydro-2-thiopyrimid-5-ylidene)allylidene 3 methylthio-6-phenyl-lH-pyraz- 2 olo[3,2-c]-s-triazole 5 (lhHs 2115 N CH=CHCH =S I N N CgH5 NH CHaS N EXAMPLE 33 3-etl1yl-2,4'- 3-methylthio-6-phenyl-7H-pyrazolo [3 ,2-c]-striazol-7-ylidene) but-2'-enylidenebenzthiazoline (Compound 33) Fl,a...

Compound 15 (0.46 gram), 2,4-acetanilidobutadienylbenzthiazole ethiodide(0.95 gram) were dissolved in boiling ethanol ml.) Triethylamine (1 ml.)was added and a deep blue dye was formed. The mixture was heated underreflux for 5 minutes and on chilling dark blue needles separated. Theproduct (0.6 gram) was collected and rerecrystallised twice frommethanol. The dye had M methanol at 619 nm.

EXAMPLE 34 A sensitizing amount (i.e. 200 mg./mole of silver) of each ofdye compounds 25, 30, 29, 31, 26 and 33 indi- 70 cated in the tablebelow was added to separate portions of a negatvie-type, developing outgelatino silver chlorobromide emulsion. Each of these emulsions wascoated onto a piece of cellulose ester film support and dried.Spectrographic exposures were made on each coating and these weredeveloped in a photographic developer having the following com ositionsGrams p-Methyl aminophenol sulphate 2.0 Sodium sulphite desicated 90.0Hydroquinone 8.0 Sodium carbonate monohydrate 52.5 Potassium bromide 5.0

Water to make 1 litre,

fixed in a conventional sodium thiosulphate fixing bath, washed anddried. The following table summarizes the wavelength of light to whichthe maximum sensitivity is produced, and the longest wavelength light towhich each emulsion is sensitized.

Wavelength of light in mm. to which:

6-heptadecyl-3-methy1thio-1 H-pyrazolo [3 ,2-c] -s-triazole (0.2 gram)was dissolved in dibutyl phthalate (0.4 ml.) at C. A hot solution (80C.) of 10% inert bone gelatin (12.8 ml.) and 5% tri-isopropylnaphthalenesulphonate (1.2 ml.) were added to the coupler solution and the mixturewas homogenized using an ultrasonic probe. Water (8.8 ml.) and 7.5%solution of saponin (0.9 ml.) were added and the mixture was filtered. Agelatino bromo-iodide emulsion (6.8 grams containing 0.69 gram silver)was added to the filtrate and the mixture was coated on a celluloseacetate film base at 425 mg. gelatin/ sq. ft. dry weight and thelight-sensitive material so obtained was exposed and then developed for10 minutes at 68 F. in a colour developer of the following composi-Water to make 1,000 ml. and pH adjusted ot 10.9

The development was followed by acid stop-fix, ferricyanide bleach andfinally fixation stages when a magenta image was formed in the exposedregions by the formation of a dye having an absorption maximum at 559nm. Other developing agents can be used for example, 3-methyl-4-amino-N- 8-methylsulphonarnidoethyl-N ethylaniline gives a dyewith absorption maximum at 555 nm.

EXAMPLE 36 A colour developer solution having the formula:

Grams Sodium sulphite 2 2-amino-5-diethylamino toluene hydrochloride 2Sodium carbonate 20 Potassium bromide 2 Compound 5 (in ethanolsufiicient to dissolve coupler) 1.5 Water to 1 litre.

pH adjusted to 11.5 with sodium hydroxide solution was used to colourdevelop a magenta image in a strip of image exposed film coated with alayer of silver halide emulsion. The silver in the strip was convertedto silver halide by treating it with a ferricyanidebrornide bleach andthen the silver halide was removed by treating the strip with a hypo fixbath to leave a magenta dye image having an absorption maximum at 557nm. A magenta dye image having an absorption maximum at 570 nm. wasobtained when 3-methylthio-6-phenyl-1H-pyrazolo[3,2-c]-s-triazole(Compound 15 is used as the coupler and N,N-diethyl-pphenylenediamine asthe developing agent in the above formula.)

'Our dyes, especially those of Formulas III, VI and VIII are usedadvantageously as spectral sensitizers for photographic silver halideemulsions when incorporated there in. Dyes of Formula IV are used toadvantage in hydrophilic colloid light-absorbing filter layers forphotographic elements. These dyes are bleached by the action ofconventional developer solutions.

The sensitizing dyes of our invention are especially useful forextending the spectral sensitivity of the customarily employed silverchloride, silver chlorobromide, silver bromide, silver bromoiodide andsilver chlorobromoiodide developing out emulsions using a hydrophiliccolloid carrier such as gelatin, its water-soluble derivatives,polyvinyl alcohol, its water-soluble derivatives and copolymers,water-soluble vinyl polymers, such as polyacrylamide, imidized polyacrylamide, etc., and other watersoluble film-forming materials thatform water-permeable coatings, such as colloidal albumin, water-solublecellulose derivatives like ethylanolamine cellulose acetate, etc. Toprepare emulsions sensitized with one or more of our new dyes, it isonly necessary to disperse the dye or dyes in the emulsions. The methodsof incorporating dyes in emulsions are simple and well known to thoseskilled in the art. In practice, it is convenient ot add the dyes to theemulsion in the form of a solution in a suitable solvent. Methanol,ethanol, propanol, etc., acetone and pyridine are used to advantage. Thedyes are advantageously incorporated in the finished, washed emulsions,and should be uniformly distributed throughout the emulsions.

The concentration of the dyes in the emulsions can vary widely, and willdepend upon the type of emulsion and the effect desired. The suitableand most economical concentration for any given emulsion will beapparent to those skilled in the art, upon making the ordinary tests andobservations customarily used in the art of emulsion making.

To prepare a hydrophilic colloid-silver halide emulsion sensitized withone or more of our new dyes, the following procedure is satisfactory. Aquantity of dye is dissolved in a suitable solvent, such as an alcohol,acetone, pyridine, etc., and a volume of this solution, which may bediluted with water, containing the dye, is slowly added to about 1000cc. of gelatino-silver halide emulsion, with stirring. Stirring iscontinued until the dye is uniformly dispersed in the emulsion.

The above statements are only illustrative, as it will be apparent thatthe dyes can be incorporated in photographic emulsions by any of theother methods customarily employed in the art, e.g., by bathing a plateor film upon which an emulsion is coated in a solution of the dye in anappropriate solvent. However, bathing methods are ordinarily not to bepreferred. Emulsions sensitized with the dyes can be coated on suitablesupports, such as glass, cellulose derivative film, resin film or paperin the usual manner.

EXAMPLE 37 A sensitizing amount of each of the dyes indicated in thetable below is added to separate portions of an ordinary gelatino silverchlorobromide emulsion. Each of these emulsions is coated on a piece ofcellulose ester support and dried. Spectrographic exposures are made at1 second on each coating and these are developed at room temperature ina photographic developer having the composition:

Grams p-Methylaminophenol sulfate 2.0 Sodium sulfite, desiccated 90.0

Grams Hydroquinone 8.0 Sodium carbonate-H 0 52.5 Potassium bromide 5.0

Water to make 1 liter.

fixed in a conventional sodium thiosulfate fixing bath, washed anddried. The following table summarizes the wavelength of light to whichthe maximum sensitivity is produced and the longest wavelength light towhich each emulsion is sensitized.

Wavelength of light in nm. to which:

1 In the presence of Leucophor B (a registered trademark) brightiner.

Similar results are obtained when Example 15 is repeated using othersilver halide emulsions. Similarly it can be shown that other of ourdyes such as those listed immediately after Examples 1, 3, 4, and 10 arevaluable spectral sensitizers for photograuphic silver halide emulsions.

Our novel spectrally sensitized silver halide emulsions areadvantageously used in making color photographic elements that are colordeveloped with color developers that contain the color-forming couplersor used in making color photographic elements that incorporate thecolor-forming couplers in the emulsions. Any of the cyan, yellow andmagenta dye-forming couplers used in color photography are used toadvantage to form a dye image in our emulsions.

EXAMPLE 38 A batch of aqueous gelatin is divided into 5 portions towhich samples of the dyes of Examples 1, 2, 3, 4, and 5 are added. Thedye of Example 1 is added in pyridine solution while the dyes ofExamples 2, 3, 4 and 5 are added in methanol solution. The dyed portionsof aqueous gelatin are coated on pieces of film support as useful filterlayers for photographic elements.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

We claim:

1. A light-sensitive photographic silver halide emulsion containing amethine dye having two lH-pyrazolo- [3,2-c]-s-triazole nuclei connectedto each other through the carbon atom in the 7 position of said nucleiby a conjugated methine linkage having an odd number of from 1 to 5carbon atoms in the said linkage.

2. A light-sensitive photographic silver halide emulsion containing amethine dye having two nuclei, one of said nuclei being alH-pyrazolo[3,2-c1-s-triazole nucleus attached at the carbon atom in the7 position through a double bond or a conjugated methine linkage of from1 to 5 carbon atoms in the said linkage to a carbon atom in a secondnucleus having the formula wherein R and R each represent a memberselected from the class consisting of a hydrogen, alkyl, aryl,heterocyclic, amino, acylamido, hydroxy, alkoxy, carboxy and esterifiedcarboxy group; R represents an alkyl or a phenyl group; Z represents theatoms necessary to complete an acidic heterocyclic ketomethylene nucleushaving 5-6 atoms in the heterocyclic ring; Z represents the atomsnecessary to complete a heterocyclic basic nucleus having 5-6 atoms inthe hcterocyclic ring; m is an integer of -1.

3. A light-sensitive photographic element comprising a support, ahydrophilic colloid silver halide emulsion layer and at least one layercontaining a dye having the formulae:

wherein R, R R and R each represent a member selected from the classconsisting of a hydrogen, alkyl, aryl, heterocyclic, amino, acylamido,hydroxyl, alkoxy, carboxy, and esterified carboxy group; Q represents aor a Q represents a 0:0 group in which R is an alkyl or a phenyl group;L is defined as a methine group; n is an integer of from 0 to 2;

Z represents the atoms necessary to complete an acidic heterocyclicketomethylene nucleus having 5-6 atoms in the heterocyclic ring; Zrepresents the atoms necessary to complete a heterocyclic basic nucleushaving 5-6 atoms in the heterocyclic ring; and m is an integer of 0-1.

4. A light-sensitive photographic silver halide emulsion of claim 2wherein the second nucleus linked to said 1H- pyrazolo[3,2-c]-s-triazolenucleus is 5. A light-sensitive photographic silver halide emulsioncontaining a methine dye having two nuclei, one of said nuclei attachedat the carbon atom in the 7 position through a double bond or aconjugated methine linkage of from 1 to 5 carbon atoms in the saidlinkage to a carbon atom in a second nucleus, said second nucleus beinga 11-1- being a IH-pyrazolo[3,2-c]-s-triazole nucleus pyrazolo[3,2-c] striazole nucleus, a hydantoin, a thinhydantoin, a rhodanine, abarbituric acid, a thiobarbituric acid, an imidazolone, a2-pyrazolinone, an indandione, a thiazole, a benzothiazole, anaphthothiazole, an oxazole, a benzoxazole, a naphthoxazole, aselenazole, a benzoselenazole, a naphthoselenazole, a thiazoline, apyridine, a quinoline, an isoquinoline, an imidazole, a benzimidazole,or a naphthimidazole group.

6. A light-sensitive photographic silver halide emulsion containing asensitizing amount of 7-(6-methyl 3 phenyl 1H pyrazolo[3,2-c]-s-triazol-7ylidene)methylene 6 methyl 3 phenyl 1H- pyrazolo[3,2-c]-s-triazole. 7.A light-sensitive photographic silver halide emulsion containing asensitizing amount of 7-(3,6 dimethyl 1H pyrazolo[3,2-c]-s-triazol 7-ylidene) 3' allylidene 3,6 dimethyl-lH-pyrazolo- [3 ,2-c] -s-triazole.8. A light-sensitive photographic silver halide emulsion containing asensitizing amount of 3-ethyl 2 (3,6 dimethyl 1Hpyrazolo[3,2-c]-striazol-7-ylidene)-2-ethylidenebenzthiazoline. 9. Alight-sensitive photographic silver halide emulsion containing asensitizing amount of 3-ethyl 2 (6 methyl 3 p methoxyphenyl 1H-pyrazolo[3,2-c]-s-triazol 7 ylidene) 2' ethylidene- 'benzothiazoline.10. A light-sensitive photographic silver halide emulsion containing asensitizing amount of 7-(1,3-diethyl 4,6 dioxo-hexahydro 2thio-5-pyrimidylidene) 3 allylidene 3 pdimethylaminophenyl-6-methyl-lH-pyrazolo[3,2-c]-s-triazole. 11. Alight-sensitive photographic silver halide emulsion containing asensitizing amount of 7-(3-methylthio 6 phenyl 7Hpyrazolo[3,2-c]-striazol 7 ylidene)-methylene 3 methylthio 6-phenyllH-pyrazolo [3 ,2-c] -s-triazole. 12. A light-sensitivephotographic silver halide emulsion containing a sensitizing amount of3-ethyl 2 -(3 methylthio 6 phenyl-7H-pyrazolo- [3,2-c]-s-triazole-7-ylidene) benzthiazoline. 13. A light-sensitivephotographic silver halide emulsion containing a sensitizing amount of3-methylthio 7 p nitrobenzylidene 6 phenyl-7H- pyrazolo[3,2-c]s-triazole. 14. A light-sensitive photographic silver halide emulsioncontaining a sensitizing amount of 7-(l-ethyl 2,5 dimethyl 3pyrryl)methylene 3- methylthio 6 phenyl 7H pyrazolo[3,2-c] striazole.15. A light-sensitive photographic silver halide emulsion containing asensitizing amount of 3-ethyl 2,2 (3-methylthio 6 phenyl 1H pyrazolo- [3,2-c] -s-triazole-7-ylidene) ethyli deneb enzoxazoline. 16. Alight-sensitive photographic silver halide emulsion containing asensitizing amount of v 3-ethyl 2,4 (3-rnethy1thio 6 phenyl 7H pyrazolo-[3,2-c]-s-triazole 7 ylidene)but 2' enylidenebenzthiazoline.

References Cited UNITED STATES PATENTS 2,887,480 5/1929 Webster et al.96-132 3,598,595 8/1971 Mee et al. 96132 3,615,639 10/1971 Carpenter etal. 96-101 J. TRAVIS BROWN, Primary Examiner US. Cl. X.R.

"H050 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTEON Patent No.,758,509 Dated September 11, 1973 Inventor) Joseph Bailey, Edward B.Knott and Peter A. Marr It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrect-ed as shown below:

Column 2, line 64, 'ynaphthyl" should read a -naphthyl Column 3, line 6,"yor" should read (1 or Column 8, line 34, "given" should read---give--;

Column 11, line 47, 'Z-methylthiO" should read S-methylthio Column 12,line 46, "0.2" should read -0.4 2;

Signed and sealed this 26th day of March 197b,.

(SEAL) Attest:

EDWARD l T.FLETCHER,JR. C. MARSILALL DANN Attesting Officer Commissionerof Patents

